PIK3CA and mismatch repair cancer syndrome 1: For physical activity, the current results indicate a role of molecular features (KRASmut, PIK3CAmut, BRAFmut, and/or MMR deficiency) in the etiological pathway between physical inactivity and colon cancer risk in women (physical activity was associated with any-mutation/dMMR colon cancer), and it seems that in particular PIK3CA mutations are involved in this association (strongest association observed with PIK3CAmut colon cancer).